Recycled steel and various other metals can be used to make a myriad of products.

Cast iron is a more generic term

There are many types of cast-iron alloys, but the four primary categories include white cast-iron, gray cast-iron, ductile cast iron, and malleable cast-iron.

In order to get a consistent "Batch" at the foundry the materials have to be a well managed blend of several given substances.....

Bumpers off a few Toyota pickup's, a handful of rail road track and sundry cast brackets from ancient tractors is not gonna cut it...

Repeatable mixtures of the required elements in huge quantity are required.

I do believe most recycled materials are used for more mundane items.....A batch of fenders made from scrap car bodies.....VERY POSSIBLE

We have an outfit locally that takes in huge quantities of scrap steel....They turn out rebar and steel T posts (The green/white fence posts)
They ship out huge rolls of rebar every day...

Steel sheets and such can be made from a lot of recycled materials.....

Engine blocks have to be a bit tighter on the mix...Steel fenders can't be made into cast iron....

MY OTHER POST ABOUT WHAT WAS USED WAS A BIT OF TONGUE IN CHEEK..